MINOR: standard: add RFC HTTP date parser
This parser takes a string containing an HTTP date. It returns
a broken-down time struct. We must considers considers this
time as GMT. Maybe later the timezone will be taken in account.
diff --git a/src/standard.c b/src/standard.c
index 1b158e2..67c82c7 100644
--- a/src/standard.c
+++ b/src/standard.c
@@ -16,6 +16,7 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <time.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
@@ -24,10 +25,17 @@
#include <common/chunk.h>
#include <common/config.h>
#include <common/standard.h>
+#include <common/tools.h>
#include <types/global.h>
#include <proto/dns.h>
#include <eb32tree.h>
+/* This macro returns false if the test __x is false. Many
+ * of the following parsing function must be abort the processing
+ * if it returns 0, so this macro is useful for writing light code.
+ */
+#define RET0_UNLESS(__x) do { if (!(__x)) return 0; } while (0)
+
/* enough to store NB_ITOA_STR integers of :
* 2^64-1 = 18446744073709551615 or
* -2^63 = -9223372036854775808
@@ -2542,6 +2550,369 @@
return dst;
}
+/* This function check a char. It returns true and updates
+ * <date> and <len> pointer to the new position if the
+ * character is found.
+ */
+static inline int parse_expect_char(const char **date, int *len, char c)
+{
+ if (*len < 1 || **date != c)
+ return 0;
+ (*len)--;
+ (*date)++;
+ return 1;
+}
+
+/* This function expects a string <str> of len <l>. It return true and updates.
+ * <date> and <len> if the string matches, otherwise, it returns false.
+ */
+static inline int parse_strcmp(const char **date, int *len, char *str, int l)
+{
+ if (*len < l || strncmp(*date, str, l) != 0)
+ return 0;
+ (*len) -= l;
+ (*date) += l;
+ return 1;
+}
+
+/* This macro converts 3 chars name in integer. */
+#define STR2I3(__a, __b, __c) ((__a) * 65536 + (__b) * 256 + (__c))
+
+/* day-name = %x4D.6F.6E ; "Mon", case-sensitive
+ * / %x54.75.65 ; "Tue", case-sensitive
+ * / %x57.65.64 ; "Wed", case-sensitive
+ * / %x54.68.75 ; "Thu", case-sensitive
+ * / %x46.72.69 ; "Fri", case-sensitive
+ * / %x53.61.74 ; "Sat", case-sensitive
+ * / %x53.75.6E ; "Sun", case-sensitive
+ *
+ * This array must be alphabetically sorted
+ */
+static inline int parse_http_dayname(const char **date, int *len, struct tm *tm)
+{
+ if (*len < 3)
+ return 0;
+ switch (STR2I3((*date)[0], (*date)[1], (*date)[2])) {
+ case STR2I3('M','o','n'): tm->tm_wday = 1; break;
+ case STR2I3('T','u','e'): tm->tm_wday = 2; break;
+ case STR2I3('W','e','d'): tm->tm_wday = 3; break;
+ case STR2I3('T','h','u'): tm->tm_wday = 4; break;
+ case STR2I3('F','r','i'): tm->tm_wday = 5; break;
+ case STR2I3('S','a','t'): tm->tm_wday = 6; break;
+ case STR2I3('S','u','n'): tm->tm_wday = 7; break;
+ default: return 0;
+ }
+ *len -= 3;
+ *date += 3;
+ return 1;
+}
+
+/* month = %x4A.61.6E ; "Jan", case-sensitive
+ * / %x46.65.62 ; "Feb", case-sensitive
+ * / %x4D.61.72 ; "Mar", case-sensitive
+ * / %x41.70.72 ; "Apr", case-sensitive
+ * / %x4D.61.79 ; "May", case-sensitive
+ * / %x4A.75.6E ; "Jun", case-sensitive
+ * / %x4A.75.6C ; "Jul", case-sensitive
+ * / %x41.75.67 ; "Aug", case-sensitive
+ * / %x53.65.70 ; "Sep", case-sensitive
+ * / %x4F.63.74 ; "Oct", case-sensitive
+ * / %x4E.6F.76 ; "Nov", case-sensitive
+ * / %x44.65.63 ; "Dec", case-sensitive
+ *
+ * This array must be alphabetically sorted
+ */
+static inline int parse_http_monthname(const char **date, int *len, struct tm *tm)
+{
+ if (*len < 3)
+ return 0;
+ switch (STR2I3((*date)[0], (*date)[1], (*date)[2])) {
+ case STR2I3('J','a','n'): tm->tm_mon = 0; break;
+ case STR2I3('F','e','b'): tm->tm_mon = 1; break;
+ case STR2I3('M','a','r'): tm->tm_mon = 2; break;
+ case STR2I3('A','p','r'): tm->tm_mon = 3; break;
+ case STR2I3('M','a','y'): tm->tm_mon = 4; break;
+ case STR2I3('J','u','n'): tm->tm_mon = 5; break;
+ case STR2I3('J','u','l'): tm->tm_mon = 6; break;
+ case STR2I3('A','u','g'): tm->tm_mon = 7; break;
+ case STR2I3('S','e','p'): tm->tm_mon = 8; break;
+ case STR2I3('O','c','t'): tm->tm_mon = 9; break;
+ case STR2I3('N','o','v'): tm->tm_mon = 10; break;
+ case STR2I3('D','e','c'): tm->tm_mon = 11; break;
+ default: return 0;
+ }
+ *len -= 3;
+ *date += 3;
+ return 1;
+}
+
+/* day-name-l = %x4D.6F.6E.64.61.79 ; "Monday", case-sensitive
+ * / %x54.75.65.73.64.61.79 ; "Tuesday", case-sensitive
+ * / %x57.65.64.6E.65.73.64.61.79 ; "Wednesday", case-sensitive
+ * / %x54.68.75.72.73.64.61.79 ; "Thursday", case-sensitive
+ * / %x46.72.69.64.61.79 ; "Friday", case-sensitive
+ * / %x53.61.74.75.72.64.61.79 ; "Saturday", case-sensitive
+ * / %x53.75.6E.64.61.79 ; "Sunday", case-sensitive
+ *
+ * This array must be alphabetically sorted
+ */
+static inline int parse_http_ldayname(const char **date, int *len, struct tm *tm)
+{
+ if (*len < 6) /* Minimum length. */
+ return 0;
+ switch (STR2I3((*date)[0], (*date)[1], (*date)[2])) {
+ case STR2I3('M','o','n'):
+ RET0_UNLESS(parse_strcmp(date, len, "Monday", 6));
+ tm->tm_wday = 1;
+ return 1;
+ case STR2I3('T','u','e'):
+ RET0_UNLESS(parse_strcmp(date, len, "Tuesday", 7));
+ tm->tm_wday = 2;
+ return 1;
+ case STR2I3('W','e','d'):
+ RET0_UNLESS(parse_strcmp(date, len, "Wednesday", 9));
+ tm->tm_wday = 3;
+ return 1;
+ case STR2I3('T','h','u'):
+ RET0_UNLESS(parse_strcmp(date, len, "Thursday", 8));
+ tm->tm_wday = 4;
+ return 1;
+ case STR2I3('F','r','i'):
+ RET0_UNLESS(parse_strcmp(date, len, "Friday", 6));
+ tm->tm_wday = 5;
+ return 1;
+ case STR2I3('S','a','t'):
+ RET0_UNLESS(parse_strcmp(date, len, "Saturday", 8));
+ tm->tm_wday = 6;
+ return 1;
+ case STR2I3('S','u','n'):
+ RET0_UNLESS(parse_strcmp(date, len, "Sunday", 6));
+ tm->tm_wday = 7;
+ return 1;
+ }
+ return 0;
+}
+
+/* This function parses exactly 1 digit and returns the numeric value in "digit". */
+static inline int parse_digit(const char **date, int *len, int *digit)
+{
+ if (*len < 1 || **date < '0' || **date > '9')
+ return 0;
+ *digit = (**date - '0');
+ (*date)++;
+ (*len)--;
+ return 1;
+}
+
+/* This function parses exactly 2 digits and returns the numeric value in "digit". */
+static inline int parse_2digit(const char **date, int *len, int *digit)
+{
+ int value;
+
+ RET0_UNLESS(parse_digit(date, len, &value));
+ (*digit) = value * 10;
+ RET0_UNLESS(parse_digit(date, len, &value));
+ (*digit) += value;
+
+ return 1;
+}
+
+/* This function parses exactly 4 digits and returns the numeric value in "digit". */
+static inline int parse_4digit(const char **date, int *len, int *digit)
+{
+ int value;
+
+ RET0_UNLESS(parse_digit(date, len, &value));
+ (*digit) = value * 1000;
+
+ RET0_UNLESS(parse_digit(date, len, &value));
+ (*digit) += value * 100;
+
+ RET0_UNLESS(parse_digit(date, len, &value));
+ (*digit) += value * 10;
+
+ RET0_UNLESS(parse_digit(date, len, &value));
+ (*digit) += value;
+
+ return 1;
+}
+
+/* time-of-day = hour ":" minute ":" second
+ * ; 00:00:00 - 23:59:60 (leap second)
+ *
+ * hour = 2DIGIT
+ * minute = 2DIGIT
+ * second = 2DIGIT
+ */
+static inline int parse_http_time(const char **date, int *len, struct tm *tm)
+{
+ RET0_UNLESS(parse_2digit(date, len, &tm->tm_hour)); /* hour 2DIGIT */
+ RET0_UNLESS(parse_expect_char(date, len, ':')); /* expect ":" */
+ RET0_UNLESS(parse_2digit(date, len, &tm->tm_min)); /* min 2DIGIT */
+ RET0_UNLESS(parse_expect_char(date, len, ':')); /* expect ":" */
+ RET0_UNLESS(parse_2digit(date, len, &tm->tm_sec)); /* sec 2DIGIT */
+ return 1;
+}
+
+/* From RFC7231
+ * https://tools.ietf.org/html/rfc7231#section-7.1.1.1
+ *
+ * IMF-fixdate = day-name "," SP date1 SP time-of-day SP GMT
+ * ; fixed length/zone/capitalization subset of the format
+ * ; see Section 3.3 of [RFC5322]
+ *
+ *
+ * date1 = day SP month SP year
+ * ; e.g., 02 Jun 1982
+ *
+ * day = 2DIGIT
+ * year = 4DIGIT
+ *
+ * GMT = %x47.4D.54 ; "GMT", case-sensitive
+ *
+ * time-of-day = hour ":" minute ":" second
+ * ; 00:00:00 - 23:59:60 (leap second)
+ *
+ * hour = 2DIGIT
+ * minute = 2DIGIT
+ * second = 2DIGIT
+ *
+ * DIGIT = decimal 0-9
+ */
+int parse_imf_date(const char *date, int len, struct tm *tm)
+{
+ RET0_UNLESS(parse_http_dayname(&date, &len, tm)); /* day-name */
+ RET0_UNLESS(parse_expect_char(&date, &len, ',')); /* expect "," */
+ RET0_UNLESS(parse_expect_char(&date, &len, ' ')); /* expect SP */
+ RET0_UNLESS(parse_2digit(&date, &len, &tm->tm_mday)); /* day 2DIGIT */
+ RET0_UNLESS(parse_expect_char(&date, &len, ' ')); /* expect SP */
+ RET0_UNLESS(parse_http_monthname(&date, &len, tm)); /* Month */
+ RET0_UNLESS(parse_expect_char(&date, &len, ' ')); /* expect SP */
+ RET0_UNLESS(parse_4digit(&date, &len, &tm->tm_year)); /* year = 4DIGIT */
+ tm->tm_year -= 1900;
+ RET0_UNLESS(parse_expect_char(&date, &len, ' ')); /* expect SP */
+ RET0_UNLESS(parse_http_time(&date, &len, tm)); /* Parse time. */
+ RET0_UNLESS(parse_expect_char(&date, &len, ' ')); /* expect SP */
+ RET0_UNLESS(parse_strcmp(&date, &len, "GMT", 3)); /* GMT = %x47.4D.54 ; "GMT", case-sensitive */
+ tm->tm_isdst = -1;
+ tm->tm_gmtoff = 0;
+ return 1;
+}
+
+/* From RFC7231
+ * https://tools.ietf.org/html/rfc7231#section-7.1.1.1
+ *
+ * rfc850-date = day-name-l "," SP date2 SP time-of-day SP GMT
+ * date2 = day "-" month "-" 2DIGIT
+ * ; e.g., 02-Jun-82
+ *
+ * day = 2DIGIT
+ */
+int parse_rfc850_date(const char *date, int len, struct tm *tm)
+{
+ int year;
+
+ RET0_UNLESS(parse_http_ldayname(&date, &len, tm)); /* Read the day name */
+ RET0_UNLESS(parse_expect_char(&date, &len, ',')); /* expect "," */
+ RET0_UNLESS(parse_expect_char(&date, &len, ' ')); /* expect SP */
+ RET0_UNLESS(parse_2digit(&date, &len, &tm->tm_mday)); /* day 2DIGIT */
+ RET0_UNLESS(parse_expect_char(&date, &len, '-')); /* expect "-" */
+ RET0_UNLESS(parse_http_monthname(&date, &len, tm)); /* Month */
+ RET0_UNLESS(parse_expect_char(&date, &len, '-')); /* expect "-" */
+
+ /* year = 2DIGIT
+ *
+ * Recipients of a timestamp value in rfc850-(*date) format, which uses a
+ * two-digit year, MUST interpret a timestamp that appears to be more
+ * than 50 years in the future as representing the most recent year in
+ * the past that had the same last two digits.
+ */
+ RET0_UNLESS(parse_2digit(&date, &len, &tm->tm_year));
+
+ /* expect SP */
+ if (!parse_expect_char(&date, &len, ' ')) {
+ /* Maybe we have the date with 4 digits. */
+ RET0_UNLESS(parse_2digit(&date, &len, &year));
+ tm->tm_year = (tm->tm_year * 100 + year) - 1900;
+ /* expect SP */
+ RET0_UNLESS(parse_expect_char(&date, &len, ' '));
+ } else {
+ /* I fix 60 as pivot: >60: +1900, <60: +2000. Note that the
+ * tm_year is the number of year since 1900, so for +1900, we
+ * do nothing, and for +2000, we add 100.
+ */
+ if (tm->tm_year <= 60)
+ tm->tm_year += 100;
+ }
+
+ RET0_UNLESS(parse_http_time(&date, &len, tm)); /* Parse time. */
+ RET0_UNLESS(parse_expect_char(&date, &len, ' ')); /* expect SP */
+ RET0_UNLESS(parse_strcmp(&date, &len, "GMT", 3)); /* GMT = %x47.4D.54 ; "GMT", case-sensitive */
+ tm->tm_isdst = -1;
+ tm->tm_gmtoff = 0;
+
+ return 1;
+}
+
+/* From RFC7231
+ * https://tools.ietf.org/html/rfc7231#section-7.1.1.1
+ *
+ * asctime-date = day-name SP date3 SP time-of-day SP year
+ * date3 = month SP ( 2DIGIT / ( SP 1DIGIT ))
+ * ; e.g., Jun 2
+ *
+ * HTTP-date is case sensitive. A sender MUST NOT generate additional
+ * whitespace in an HTTP-date beyond that specifically included as SP in
+ * the grammar.
+ */
+int parse_asctime_date(const char *date, int len, struct tm *tm)
+{
+ RET0_UNLESS(parse_http_dayname(&date, &len, tm)); /* day-name */
+ RET0_UNLESS(parse_expect_char(&date, &len, ' ')); /* expect SP */
+ RET0_UNLESS(parse_http_monthname(&date, &len, tm)); /* expect month */
+ RET0_UNLESS(parse_expect_char(&date, &len, ' ')); /* expect SP */
+
+ /* expect SP and 1DIGIT or 2DIGIT */
+ if (parse_expect_char(&date, &len, ' '))
+ RET0_UNLESS(parse_digit(&date, &len, &tm->tm_mday));
+ else
+ RET0_UNLESS(parse_2digit(&date, &len, &tm->tm_mday));
+
+ RET0_UNLESS(parse_expect_char(&date, &len, ' ')); /* expect SP */
+ RET0_UNLESS(parse_http_time(&date, &len, tm)); /* Parse time. */
+ RET0_UNLESS(parse_expect_char(&date, &len, ' ')); /* expect SP */
+ RET0_UNLESS(parse_4digit(&date, &len, &tm->tm_year)); /* year = 4DIGIT */
+ tm->tm_year -= 1900;
+ tm->tm_isdst = -1;
+ tm->tm_gmtoff = 0;
+ return 1;
+}
+
+/* From RFC7231
+ * https://tools.ietf.org/html/rfc7231#section-7.1.1.1
+ *
+ * HTTP-date = IMF-fixdate / obs-date
+ * obs-date = rfc850-date / asctime-date
+ *
+ * parses an HTTP date in the RFC format and is accepted
+ * alternatives. <date> is the strinf containing the date,
+ * len is the len of the string. <tm> is filled with the
+ * parsed time. We must considers this time as GMT.
+ */
+int parse_http_date(const char *date, int len, struct tm *tm)
+{
+ if (parse_imf_date(date, len, tm))
+ return 1;
+
+ if (parse_rfc850_date(date, len, tm))
+ return 1;
+
+ if (parse_asctime_date(date, len, tm))
+ return 1;
+
+ return 0;
+}
+
/* Dynamically allocates a string of the proper length to hold the formatted
* output. NULL is returned on error. The caller is responsible for freeing the
* memory area using free(). The resulting string is returned in <out> if the